The present invention relates to an apparatus for the contact-free application of a liquid strip, more particularly a strip of glue, on a moving web of material, comprising at least one application head, which is provided with at least one nozzle arranged at a distance from the web of material and a valve adapted to put the nozzle into and out of operation and adapted to be operated in accordance with the desired pattern of application.
An apparatus of this type, has been proposed, see the German patent publication 3,740,045 A1, in which case the continuous application of liquid is however only possible with many problems as regards wear and insufficient freedom from failure. Such apparatus has however been evolved on the basis of device in the case of which the nozzle makes contact with the web. This is the reason why so far the valve is operated in a manner ignoring the distance between the web and the nozzle. The consequence of this is that with an increasing speed of the web ever increasing errors as regards the start and the end of the applied strip of liquid have to be tolerated, this being something which is more particularly disadvantageous in the case of the application of glue.